Apparatus and method for network slicing and slice management to support multi-slice services

ABSTRACT

The present disclosure provides an apparatus for network slicing, and an apparatus for network slice management, which are usable to support and optimize multi-slice services. The apparatuses provide functional enhancements within different layers of a network architecture. The apparatus for network slicing is configured to determine at least two correlated communication traffic flows for a service, and to bind the at least two correlated communication traffic flows. Further, it is configured to generate, and preferably expose, binding information. The apparatus for network slice management is configured to convert a service requirement of a tenant/application into a joint performance parameter in correlated network slice instances. Further, it is configured to determine a resource allocation for at least one of the network slice instances based on the joint performance parameter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/EP2018/054039, filed on Feb. 19, 2018, the disclosure of which ishereby incorporated by reference in its entirety.

STATEMENT OF FUNDING

The project leading to this application has received funding from theEuropean Union's 5G-MoNArch programme under grant agreement No 761445.

TECHNICAL FIELD

The present disclosure relates to an apparatus and to a method fornetwork slicing, in particular for identifying and exploitingcorrelations between communication traffic flows for network sliceinstances. Further, the present disclosure relates to an apparatus fornetwork slice management, in particular for a joint performancemanagement of correlated network slice instances.

BACKGROUND

The network slicing concept is introduced in 5G to address the variousdifferent requirements from multiple vertical industries assuming ashared network infrastructure (i.e. resources, devices, physical links,etc.). Network services can be customized based on the requirements ofdifferent use cases, and thus the network operation efficiency can beincreased. In 5G networks, services are implemented via network slices.The network slices are instantiated and managed by the networkmanagement system.

The 5G Infrastructure Public Private Partnership (5GPPP) architectureworking group (WG) summarizes the overall 5G slicing architectureidentified by the 5GPPP phase 1 project, which is shown in FIG. 7, asfollows: “At the service level, the slice provider offers a northboundinterface (NBI) to tenants where they can request/modify/monitor/controltheir slices according to the service-level agreements (SLAB) with theslice provider. At the network level, this implies that such on-demandNFs can be tailor-made for different devices based the level of supportneeded. The network operating system maps logical network slices to the“resources and functional” level, e.g., using various (programmable)controllers, but also virtualization techniques”

The 3rd Generation Partnership Project (3GPP) defines some basic networkslice types, e.g. enhanced Mobile Broadband (eMBB), massive Machine-TypeCommunication (mMTC), or Ultra Reliable Low Latency Communications(URLLC), wherein each network slice type is designed for a group ofservices sharing similar service requirements. However, someapplications/services may require the network features implemented bymultiple network slice types at the same time. For instance, in a remotedriving case, as it is shown in FIG. 8, High Definition (HD) video datarequires high throughput, which may be supported by the eMBB slice. Atthe same time, on-vehicle sensor data and vehicle control signalingrequire low latency but high reliability, which may be supported by theURLLC slice. Similarly, Virtual Reality (VR)/Augmented Reality (AR)applications may require an eMBB slice to transfer HD video contents,and at the same time may require a URLLC slice to transfer criticalsensor data (e.g. header direction), which decides on the actual videocontents to be transferred to the user.

In such cases of using multiple slices, the different slices may befully isolated, and their performances may be independent from eachother. However, the actual performance of each individual independentslice will affect the same service. This inevitably results in acorrelation between the requirements of the different network slices forthe same service/application. More specifically:

-   -   1. The performance of one slice affects the required Key        Performance Indicators (KPIs) of another slice. For instance, in        remote driving/AR/VR, the long latency of a video control        (direction of view) signal makes the transmission of a HD        streamed video from the vehicle site useless.    -   2. The KPI (e.g. latency) budget is actually shared between        different slices. The user experience is affected by the summary        of the latencies from multiple slices (e.g. in the above use        cases, the latency of the control signaling to the vehicle and        the latency of the video/sensor report from the vehicle).

The current 3GPP architecture does not support any cross sliceoptimization/inter-slice coordination aspects.

The current 3GPP SA5 specifies the Telecom management architecture shownin FIG. 9. The Communication Service Management Function (CSMF) isresponsible for translating the communication service relatedrequirements to network slice related requirements. The Network SliceManagement Function (NSMF) is responsible for management andorchestration of Network Slice Instances (NSI), and derives networkslice subnet related requirements from network slice relatedrequirements. The Network Slice Subnet Management Function (NSSMF) isresponsible for management and orchestration of Network Slice SubnetInstances (NSSI).

The current specification focuses on per slice service management (viaNSMF and NSSMF). There is, however, no consideration on cross sliceoptimization based on the service correlation of different slices.

The 5GPPP phase I project 5G-NORMA provides only partial cross slicemanagement and orchestration function by the introduction of an InterSlice Resource Broker (ISRB). “ISRB handles the allocation of resourcesof the different slices, their dynamic provisioning and the managementof the shared resources among them within the administrative domain itcontrols”. However, this approach focuses only on cross slice resourcemanagement, and does not explain how the cross slice management is doneacross different subnets. Further, the 5GPP phase II project 5G-MoNArchstarts the work to map 5G-NORMA architecture into the 3GPP SA5architecture, and proposes a Cross-slice Orchestration and Managementfunction. However, the detailed design and systematic framework ismissing.

SUMMARY

In view of the above-mentioned problems and disadvantages, the presentdisclosure aims to improve the conventional multi-slice serviceimplementations and approaches. The present disclosure provides acomplete framework that supports the optimization of multi-sliceservices. One particular intention of the present disclosure is toidentify and use correlations between slices instances provided for thesame service. Further, the disclosure aims at supporting inter-sliceoptimization considering multiple subnets. Another goal of the presentdisclosure is the mapping of service requirements into correlated KPIsof multiple associated network slice instances.

In particular the present disclosure proposes some functionalenhancements supporting multi-slice services in different layers(levels) of the network architecture, in order to provide a completeframework optimized in view of the multi-slice services. In particular,functional enhancements are provided in the network layer, Managementand Orchestration (MANO) layer and the service layer of a networkarchitecture, respectively.

Exploiting service correlations of network slices can help to increasethe network efficiency and to improve the user experience.

One embodiment of the present disclosure provides an apparatus fornetwork slicing, configured to determine at least two correlatedcommunication traffic flows for a service; and bind the at least twocorrelated communication traffic flows and generate binding information.

A communication traffic flow in the sense of this document may be orcomprise a Protocol Data Unit (PDU) session, General Packet RadioServices (GPRS) Tunneling Protocol (GTP) data flow, and/or Quality ofService (QoS) flow. A communication traffic flow is particularly for anetwork slice instance, i.e. related to or part of the network sliceinstance.

Correlated communication traffic flows are communication network flowsthat depend on each other with respect to one or more performanceparameters. A performance parameter, e.g. a KPI, is a parameter thatprovides a requirement for a communication network flow, for example, alatency requirement, a bandwidth requirement, a reliability requirement.It can also be a function based on at least one of the aforementionedexamples. For example if two communication network flows are correlatedwith respect to a latency requirement, this can mean that bothcommunication network flows share a latency budget defined by thelatency requirement. Two correlated communication traffic flows of twodifferent slice instances inherent the correlation between these twodifferent slice instances.

The binding information includes at least an identifier (ID) of thecommunication traffic flows.

A service in the sense of this document comprises communicationservices, e.g. requesting the establishment of one or more communicationtraffic flows, particularly PDU sessions, requesting the establishmentof one or more logical communication networks. With respect to the firstaspect, a service may particularly refer to a service requested from theterminal device (e.g. from an individual user of the network).

The apparatus of the embodiment present an important part of a completeframework that is able to support the optimization of multi-sliceservices. The apparatus is particularly able to identify and exposecorrelations between slices instances and/or communication traffic flowsfor the same service. By generating the binding information according tothe identified correlation, the apparatus enables cross slice managementand optimization, and even enables inter-slice optimization consideringmultiple subnets. The generated binding information helps significantlyto increase the network efficiency as well as to improve the userexperience.

In one embodiment, the apparatus is configured to receive a request fora service, in particular from a terminal device, and wherein thedetermination is based on the request; and/or wherein the determinationis based on pre-configured information, in particular from a tenantand/or application and/or the network.

Accordingly, different alternatives are provided for effectivelydetermining the correlation between the at least two communicationflows.

In one embodiment, the request and/or the pre-configured information forthe service includes information regarding the at least two correlatedcommunication traffic flows. Such information can be any/anycombinations of the following: PDU session ID, flow ID,source/destination IP address, source/destination port, application ID,etc.

Accordingly, the apparatus can be directly informed about whichcommunication traffic flows to consider correlated, and thus which flowsto bind.

In one embodiment, the request for the service includes informationabout a session of each of the communication traffic flows and, whereinthe request further includes network slice selection assistanceinformation for each session and/or an identity of each session.

In this implementation form the terminal device may determine thedifferent network slices that are to be used for the service. Thedifferent network slices base on different communication traffic flows.The session may e.g. be a PDU session. The request may also includeinformation about multiple sessions belonging to one or morecommunication traffic flows being for the same network slice instance.The network slice selection assistance information may be Single NetworkSlice Selection Assistance Information (S-NSSAI) specified by 3GPP e.g.as the slice identifier, and indicates the performance correlationbetween the correspondent communication traffic flows.

In one embodiment, the apparatus is configured to store a list ofsessions associated with slice selection assistance information and/orsession identities for the at least two correlated communication trafficflows.

Thus, the correlation between the at least two correlated communicationtraffic flows can be maintained and adapted as required by theapparatus. Any change of the list can be exposed. The aboveimplementation for is in particular employed in the binding of the atleast two communication traffic flows.

In one embodiment, the request for the service includes one or moreservice requirements, and the apparatus is configured to determine theat least two correlated communication traffic flows based on the one ormore service requirements.

In this implementation form, the mapping of the service to differentnetwork slices, which base on different communication flows, isperformed by the apparatus according to the overall servicerequirements.

In one embodiment, the apparatus is configured to expose the bindinginformation in at least one network layer and/or to at least one othernetwork entity, in particular access network function, core networkfunction, management function, one or more applications, and/or to oneor more network functions of the apparatus.

Exposing the binding information means making it available. Inparticular, the binding information may be exposed directly to a certainentity, function or application, or may be exposed to it indirectly viaanother network function. Any change in the binding information may beexposed immediately, or the binding information may be exposedregularly. Exposing the binding information allows other networkentities to exploit the correlation between the communication trafficflows, in order to improve support for multi-slice services.

In one embodiment, the apparatus is configured to authenticate thereceived request for the service; and map the service to the at leasttwo correlated communication traffic flows.

In this way, the apparatus may determine the different network slicesthat are to be used for the service. As mentioned above, this can betriggered by the terminal device or the apparatus, respectively.

In one embodiment, the binding of the at least two correlatedcommunication traffic flows is performed at a network layer, inparticular by an Inter Slice Coordination Function (ISCF) of theapparatus.

For the above implementation form, different implementation options arepossible at the network layer: As a first option, a new network functioncan be implemented and connected to the Service Based Architecture(SBA). As a second option, a sub function of an existing networkfunction can be implemented, wherein the network function is connectedto the SBA (e.g. Access and Mobility Management Function (AMF), PolicyControl Function (PCF) or session management function (SMF)). Thesefunctions may particularly be as defined in ‘3GPP TS23.501 SystemArchitecture for the 5G System, Stage 2 (Rel. 15)’.

Another embodiment of the present disclosure provides an apparatus fornetwork slice management configured to convert a service requirement ofa tenant/application into a joint performance parameter in correlatednetwork slice instances; determine a resource allocation for at leastone of the network slice instances based on the joint performanceparameter.

A service requirement may relate to one or more services. With respectto the second aspect, a service may particularly refer to acommunication service requested by a tenant (e.g. a vertical industrywhich use the operator network) and/or application, in particular anapplication provided by a customer, for example a vertical industry. Aperformance parameter—similar as defined above—is a parameter thatprovides a requirement for one or more network slice instances. It canbe in particular a KPI. For example, a performance requirement can be anaverage latency of all communication traffic flows in a single networkslice instance. A KPI may comprise latency, reliability, bandwidth, etc.The correlation of the correlated network slice instances may originatefrom the correlation of communication traffic flows for those networkslice instances, as described above. The communication traffic flows ofcorrelated network slice instances inherent the service requirements(e.g., KPIs) of the correlated network slice instances.

Accordingly, the apparatus of the embodiment achieves a mapping ofservice requirements into correlated KPIs of multiple associated networkslice instances, thus supporting the framework for optimizingmulti-slice services. In particular, by exploiting the correlations ofnetwork slice instances for resource allocation increases the networkefficiency and improve the user experience.

In one embodiment, the apparatus is configured to expose a jointperformance parameter to one or more functions in the network layer, inparticular a Radio Access Network (RAN) function, PCF, SMF, or AMF.

Thus, these functions can consider the joint performance parameter toe.g. apply cross slice policies (SMF/PCF), apply inter-sliceoptimization (RAN) or adjust QoS parameters (PCF). Accordingly, thesupport for multi-slice services can be improved.

In one embodiment, the apparatus is configured to instantiate the atleast two correlated network slice instances for the service based onthe resource allocation.

The slice instances can serve the same service with an optimizedperformance, particularly in terms of network efficiency. Thus, a betteruser experience can be provided.

In one embodiment, the apparatus is configured to instantiate at leasttwo sub-slices in at least one of the correlated network slice instancesbased on the resource allocation.

Accordingly, the apparatus supports slice instantiation and optimizationeven considering subnets.

In one embodiment, the apparatus is configured to receive acommunication traffic flow binding information from the network layer.

For instance, the apparatus of the second aspect can obtain the bindinginformation form the apparatus of the first aspect. The apparatus of thesecond aspect can use this binding information to identify thecorrelated communication traffic flows.

In one embodiment, the apparatus is configured to monitor the jointperformance parameter and/or the resource allocation across the at leasttwo correlated network slice instances and/or across two correlatedcommunication traffic flows.

Monitoring the performance parameter and/or per communication trafficflow performance parameter across different slice instances is thepre-requisite for an improved cross slice optimization.

In one embodiment, the apparatus is configured to expose the jointperformance parameter and/or the resource allocation across the at leasttwo correlated network slice instances and/or across at least twocorrelated communication traffic flows to the tenant/application.

For instance, this may be done via a North Bound Interface (NBI). Thetenant/application can thus make use of the joint performance parameter.

In one embodiment, the apparatus is configured to apply a joint QoStreatment to the at least two correlated network slice instances and/orthe at least two communication traffic flows based on the jointperformance parameter and/or binding information.

The QoS treatment can comprise a resource allocation and a networkconfiguration based on the KPI monitoring results. Accordingly, anoptimized QoS for the service can be provided.

In one embodiment, the apparatus is configured to manage the at leasttwo correlated network slice instances and/or the at least twosub-slices based on the joint performance parameter and/or the resourceallocation, in particular by applying a joint resource management acrossthe at least two correlated network slice instances and/or the at leasttwo sub-slices; and/or perform a service optimization across the atleast two correlated network slice instances and/or at least twosub-slices in at least two correlated network slice instances.

Accordingly, optimized support for multi-slice services can be provided,and the user experience can accordingly be improved. One sub-slice canbelong to one network slice instance and the other one can belong toanother network slice instance.

Yet another embodiment of the present disclosure provides a method fornetwork slicing, comprising determining at least two correlatedcommunication traffic flows for a service; and binding the at least twocorrelated communication traffic flows and generating bindinginformation.

In one embodiment, the method comprises receiving a request for aservice, in particular from a terminal device, and wherein thedetermination is based on the request; and/or wherein the determinationis based on pre-configured information, in particular from a tenantand/or application.

In one embodiment, the request and/or the pre-configured information forthe service includes information regarding the at least two correlatedcommunication traffic flows.

In one embodiment, the request for the service includes informationabout a session of each of the communication traffic flows and, whereinthe request further includes network slice selection assistanceinformation for each session and/or an identity of each session

In one embodiment, the method comprises storing a list of sessionsassociated with slice selection assistance information and/or sessionidentities for the at least two correlated communication traffic flows.

In one embodiment, the request for the service includes one or moreservice requirements, and the apparatus is configured to determine theat least two correlated communication traffic flows based on the one ormore service requirements.

In one embodiment, the method comprises exposing the binding informationin at least one network layer and/or to at least one other networkentity, in particular access network function, core network function,management function, one or more applications, and/or to one or morenetwork functions.

In one embodiment, the method comprises authenticating the receivedrequest for the service; and mapping the service to the at least twocorrelated communication traffic flows.

In one embodiment, the binding of the at least two correlatedcommunication traffic flows is performed at a network layer, inparticular by an Inter Slice Coordination Function (ISCF).

The method of the embodiment achieve the same advantages and effects asthe apparatus of the first aspect and its respective implementationforms. Also the same definitions and examples apply.

Still another embodiment of the present disclosure provides a method fornetwork slice management, the method comprising converting a servicerequirement of a tenant/application into a joint performance parameterin correlated network slice instances; and determining a resourceallocation for at least one of the network slice instances based on thejoint performance parameter.

In one embodiment, the method comprises exposing a joint performanceparameter to one or more functions in the network layer, in particularan RAN function, PCF, SMF, or AMF.

In one embodiment, the method comprises instantiating the at least twocorrelated network slice instances for the service based on the resourceallocation.

In one embodiment, the method comprises instantiating at least twosub-slices in at least one of the correlated network slice instancesbased on the resource allocation.

In one embodiment, the method comprises receiving a communicationtraffic flow binding information from the network layer.

In one embodiment, the method comprises monitoring the joint performanceparameter and/or the resource allocation across the at least twocorrelated network slice instances and/or across two correlatedcommunication traffic flows.

In one embodiment, the method comprises exposing the joint performanceparameter and/or the resource allocation across the at least twocorrelated network slice instances and/or across at least two correlatedcommunication traffic flows to the tenant/application.

In one embodiment, the method comprises applying a joint QoS treatmentto the at least two correlated network slice instances and/or the atleast two communication traffic flows based on the joint performanceparameter and/or binding information.

In one embodiment, the method comprises managing the at least twocorrelated network slice instances and/or the at least two sub-slicesbased on the joint performance parameter and/or the resource allocation,in particular by applying a joint resource management across the atleast two correlated network slice instances and/or the at least twosub-slices; and/or performing a service optimization across the at leasttwo correlated network slice instances and/or at least two sub-slices inat least two correlated network slice instances.

The method of the embodiment achieve the same advantages and effects asthe apparatus of the second aspect and its respective implementationforms. Also the same definitions and examples apply.

It has to be noted that all devices, elements, units and means describedin the present application could be implemented in the software orhardware elements or any kind of combination thereof. All steps whichare performed by the various entities described in the presentapplication as well as the functionalities described to be performed bythe various entities are intended to mean that the respective entity isadapted to or configured to perform the respective steps andfunctionalities. Even if, in the following description of specificembodiments, a specific functionality or step to be performed byexternal entities is not reflected in the description of a specificdetailed element of that entity which performs that specific step orfunctionality, it should be clear for a skilled person that thesemethods and functionalities can be implemented in respective software orhardware elements, or any kind of combination thereof.

BRIEF DESCRIPTION OF DRAWINGS

The above described aspects and implementation forms of the presentdisclosure will be explained in the following description of specificembodiments in relation to the enclosed drawings, in which:

FIG. 1 shows an apparatus for network slicing according to an embodimentof the present disclosure;

FIG. 2 shows a method for network slicing according to an embodiment ofthe present disclosure;

FIG. 3 shows an apparatus for network slice management according to anembodiment of the present disclosure;

FIG. 4 shows functional enhancements at different network layers andinterfaces of the network architecture provided by the framework of thepresent disclosure;

FIG. 5 shows UE-requested PDU Session Establishment for non-roaming androaming;

FIG. 6 shows a reference network architecture, to which the presentdisclosure is applicable;

FIG. 7 shows the overall 5G architecture identified by 5G-PPP Phase 1projects;

FIG. 8 shows a use case for remote driving including the communicationof HD video data and of vehicle sensor data; and

FIG. 9 shows the 3 SA5 Telecom management architecture including CSMF,NSMF, and NSSMF.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows an apparatus 100 according to an embodiment. The apparatus100 is configured for network slicing. The apparatus 100 may at leastpartly be located in a network layer 401 of a network architecture 400(see FIG. 4).

In particular, the apparatus 100 is configured to determine at least twocorrelated communication traffic flows 101 for a service. Further, theapparatus 100 is configured to bind 102 the at least two correlatedcommunication traffic flows 101, and to generate binding information103. The binding information 103 is particularly generated according tothe binding of the communication traffic flows 101.

Advantageously, the apparatus 100 can make the generated bindinginformation 103 available, for instance, in at least one network layerand/or to at least one other network entity, in particular an accessnetwork function, core network function, management function, one ormore applications, and/or to one or more network functions of theapparatus 100. Consequently, the correlation between the communicationtraffic flows 101 (and accordingly a correlation of network sliceinstances) can be exploited in the network architecture 400 foroptimized multi-slice service support.

FIG. 2 shows a method 200 according to an embodiment, particularly fornetwork slicing. The method 200 can be performed by the apparatus 100shown in FIG. 1. In particular, the method comprises a step 201 ofdetermining at least two correlated communication traffic flows 101 fora service. Further, it comprises a step 202 of binding 202 the at leasttwo correlated communication traffic flows 101 and generating bindinginformation 102.

FIG. 3 shows an apparatus 300 according to an embodiment. The apparatus300 is configured for network slice management. The apparatus 300 may beat least partly located in a service layer 403 and/or a MANO layer 402of a network architecture 400 (see FIG. 4). The apparatus 300 of FIG. 3and the apparatus 100 of FIG. 1 may be connected to each other in thenetwork architecture 400, particularly for communicating information(e.g. the binding information 102) across different layers 401, 402, 403of the network architecture 400, or may even form a single apparatus orsystem spanning multiple layers 401, 402, 403 of the networkarchitecture 400.

The apparatus 300 is in particular configured to convert a servicerequirement 301 of a tenant/application (relating to a service) into ajoint performance parameter 302 in correlated network slice instances304. Each network slicing instance may comprise at least onecommunication traffic flow. Further, the apparatus 300 is configured todetermine a resource allocation 303 for at least one of the networkslice instances 304 (e.g. a resource allocation 303 for at least onecommunication traffic flow 101 of the at least one network sliceinstance 304) based on the joint performance parameter 302. Thus, theapparatus 300 supports the optimization of multi-slice services.

FIG. 4 illustrates generally the functional enhancements achieved byimplementing the apparatus 100 and the apparatus 300, respectively, intoa network architecture 400. In particular, functional enhancements formulti-slice service support are made in different layers 401, 402 and403 of the network architecture 400. These enhancements include thefollowing:

In the service layer 403, an enhancement of service management functionand Service Level Agreement (SLA) for multi-slice service support. Inparticular, by means of implementing the apparatus 300 (here exemplarilycomprising the CSMF), the service requirements 301 oftenants/applications can be converted into at least one correlated(joint) performance parameter (here a KPI) in correlated network sliceinstances 304.

The service layer 403 enhances the Service Level Agreement (SLA)regarding the specification of the service requirements 301. Forinstance, a finer than conventional granularity of service requirements301 may be defined, which includes: joint KPIs 302 for each ofcorrelated slice instances 304, if a service is going to be implementedby multiple slices; service correlation between associated sliceinstances 304; as well as the overall service KPIs.

In the MANO layer 402, additional Management and Orchestration (MANO)functions are implemented by means of the apparatus 300 (hereexemplarily comprising the NSMF and NSSMF), in order to providemanagement support for inter-slice optimization (e.g.,monitoring/configuration cross slice (x-slice) instances, etc.). Inparticular, a cross slice MANO function may be defined both at theend-to-end (E2E) level (i.e., E2E x-slice MANO function) and subnetlevel (i.e., Domain x-slice MANO function). Further, both of the levelx-slice functions may be enhanced to support resource management crossassociated slice instances 304, KPI monitoring cross associated sliceinstances 304, and/or inter-slice service optimization cross associatedslice instances 304. For this purpose, also new interfaces may bedefined (e.g. to itself, and/or to the slice specific MANO functions) asshown in FIG. 4.

For instance, the apparatus 300 located within the MANO layer 402 maymonitor the joint performance parameter 302 and/or the resourceallocation 303 across at least two correlated network slice instances304 and/or across two correlated communication traffic flows 101.Further, the apparatus 300 may expose the joint performance parameter302 and/or the resource allocation 303 across at least two correlatednetwork slice instances 304 and/or at least two correlated communicationtraffic flows 101 to the tenant/application. The apparatus 300 may alsoapply a joint QoS treatment to at least two correlated network sliceinstances 304 and/or at least two communication traffic flows 101 basedon the joint performance parameter 302 and/or the binding information102 exposed by the apparatus 100. The apparatus 300 may also beconfigured to manage at least two correlated network slice instances 304and/or at least two sub-slices based on the joint performance parameter302 and/or the resource allocation 303 by applying a joint resourcemanagement across the at least two correlated network slice instances304 and/or the at least two sub-slices. The apparatus 300 may alsoperform a service optimization across at least two correlated networkslice instances 304 and/or at least two sub-slices in at least twocorrelated network slice instances 304.

In the network layer 401, an additional network function is implementedby the apparatus 100 (here comprising exemplarily the ISCF) to providethe associating/binding of at least two correlated communication trafficflows 101 with correlated requirements, and a mechanism to distributethe binding information 102. The apparatus 100 performs thecommunication traffic flow 101 associating/binding and the generation ofthe binding information 102 and its exposure (e.g. to different networkentities/layers). In particular, the apparatus 100 may provide thebinding information 102 from the network layer 401 to the apparatus 300located in the slice management (MANO) layer 402. Other potentialenhancements includes per UE/service/tenant cross slice policies (e.g.,PCF) and cross slice context sharing/monitoring data sharing (e.g.,NWDAF).

Further, interface enhancement between and within the different networklayers 401, 402, 403 of the network architecture 400 are provided forthe support/optimization of multi-slice services. The interfaceenhancements may include the binding information 102 exchange betweenthe network layer 401 and the MANO layer 402 (i.e. slice associationinformation), and/or an extended service requirements/performance reportexchange between the service layer 403 and the MANO layer 402 (i.e.Service req. Monitoring data), as shown in FIG. 4.

In the following, the binding of correlated communication traffic flows101 in the apparatus 100 of FIG. 1 is described in a more detailedexample (performed at the ISCF shown in FIG. 4).

The identification of correlated communication traffic flows 101 (likePDU sessions) for different network slice instances 304, is an importantpre-condition to perform service based optimization cross the sliceinstances 304. Thus, the apparatus 100 is advantageously configured toidentify correlated communication traffic flows 101, and provide thisinformation as the binding information 102 to other networkfunctions/management plane(s) for service/network performanceoptimization. It is here assumed that the PCF receivesapplication/service requirements 301 from the AF. The PCF can thendecide on one or more flow level/PDU session level cross slice policies,e.g. it can decide on the QoS profile for the associated QoS flows(e.g., ARP, 5QI), and/or decide on the policies for associated PDUsessions (e.g., UPF selection, etc.).

FIG. 5 shows as example a User Equipment (UE)-requested PDU Sessionestablishment for non-roaming and roaming with local breakout as definedin 3GPP TS 23.502 V15.0.0 (2017-12). This includes conventionally:

-   1. “From UE to AMF: NAS Message (S-NSSAI, DNN, PDU Session ID,    Request type, Old PDU Session ID, N1 SM container (PDUSession    Establishment Request)).”-   2. “The AMF selects an SMF as described in clause 4.3.2.2.3. If the    Request Type indicates “Initial request” or the request is due to    handover from EPS, the AMF stores an association of the S-NSSAI, the    PDU Session ID and the SMF ID.”

For supporting the binding of the correlated communication traffic flows101 related to network slice instances 304, the following enhancementsmay be provided according to the present disclosure to the UE sessionmanagement procedure of FIG. 5:

-   -   The UE 501 may sends a PDU session establishment request to the        AMF 503 with multiple PDU sessions, and each PDU session may be        associated with its own S-NSSAI. For example, one application        may have multiple IP addresses and each IP address may be used        for one PDU Session with a different NSSAI. The UE 501 may also        use a NSSP (Network Slice Selection Policy) to map one        application to multiple slices.    -   An example modification for the conventional UE-requested PDU        session Establishment may accordingly be (note underlined):

-   1. “From UE to AMF: NAS Message (list of (S-NSSAI, DNN, PDU Session    ID, Request type, Old PDU Session ID, N1 SM container (PDU Session    Establishment Request))).”    -   In a further implementation, the UE 501 may send a PDU session        establishment request to the AMF 502, and may indicate the IDs        of the associated PDU sessions.

An example modification for the conventional UE-requested PDU sessionEstablishment may accordingly be (note underlined):

-   1. “From UE to AMF: NAS Message (S-NSSAI, DNN, PDU Session ID,    Request type, Old PDU Session ID, associated PDU session ID(s), N1    SM container (PDU Session Establishment Request)).”    -   The AMF (ISCF) 503 optionally stores a list of correlated PDU        session ID, S-NSSAI, SMF ID association.    -   An example modification for the conventional UE-requested PDU        session Establishment may accordingly be (note underlined):-   2. “The AMF selects an SMF as described in clause 4.3.2.2.3. If the    Request Type indicates “Initial request” or the request is due to    handover from EPS, the AMF stores an association of the S-NSSAI, the    PDU Session ID and the SMF ID. In case of multiple correlated PDU    sessions, AMF stores a list of the aforementioned association.”

Next, the providing of the binding information 102 concerning the atleast two correlated communication traffic flows 101 of slice instances304 in the apparatus 100 of FIG. 1 is described in a more detail examplewith respect to FIG. 5. In this implementation, ISCF is implemented as asub function of AMF.

-   -   The AMF 503 provides the binding information 102 of e.g.        correlated PDU sessions to other network entities (e.g. to the        PCF 506, the SMF 505, a Network Data Analytics Function (NWDAF),        the RAN 502, management plane, etc.).    -   In an example implementation, the AMF 503 provides the binding        information 102 to other network functions using a Service Based        Interface (SBI) as is shown in the below table in 3GPP format        (note underlined).

Reference in Service Name Description TS 23.502 [3] Example Consumer(s)Namf_Communication This service enables an NF to communicate 5.2.2.2SMF, SMSF, PCF, NEF, Peer AMF with the UE and/or the AN through the AMF.Namf_EventExposure This service enables other NFs to subscribe 5.2.2.3SMF, NEF, PCF, UDM or get notified of the mobility related events andstatistics. Namf_MT This service enables an NF to make 5.2.2.4 SMSF sureUE is reachable. Namf_ISCF This service provide slice  SMF, NEF, PCFassociation for multi-slice service

In a further example implementation, the AMF 503 provides thisinformation to SMF 505 using N11 interface. An example modification mayaccordingly be (note underlined):

-   3. From AMF to SMF: Either Nsmf_PDUSession_CreateSMContext Request    (SUPI, DNN, S-NSSAI, PDU Session ID, associated PDU session ID(s),    AMF ID, Request Type, N1 SM container (PDUSession Establishment    Request), User location information, Access Type, PEI, GPSI,    Subscription For PDU Session Status Notification) or    Nsmf_PDUSession_UpdateSMContext Request (SUPI, DNN, S-NSSAI, PDU    Session ID, associated PDU session ID(s), AMF ID, Request Type, N1    SM container (PDU Session Establishment Request), User location    information, Access Type, RAT type, PEI).”    -   In another example implementation, the AMF 503 provides this        information to RAN 502 using N2 interface. An example        modification may accordingly be (note underlined):-   12. AMF to (R)AN: N2 PDU Session Request (N2 SM information,    associated PDU session ID(s), NAS message (PDU Session ID, N1 SM    container (PDU Session Establishment Accept))).

Example usages of the exposed binding information 102 at differentnetwork functions may be as follows:

-   -   The SMF 505 may identify the instances 304 of correlated QoS        flows/PDU sessions (based on the binding information 102        received from the ISCF and based on local QoS flow to PDU        session mapping) and may apply cross slice policies from the PCF        506.    -   The RAN 502 may receive the correlated PDU session binding        information 102 from the AMF (ISCF) 503 and may receive a        mapping from PDU session to QoS flows from the SMF 505, and may        apply inter-slice optimization from the RAN perspective.    -   Based on the monitored performance from one of the associated        (correlated) slice instances 304, the PCF 506 may adjust one or        more QoS parameters for the other slice instance 304.

Next, the mapping of a service to logical network slices is described ina more detailed example. This mapping can be either done by thetenants/customers themselves or by the network (particularly theapparatus 100 and/or 300 provided in the network).

-   -   The procedure may be as follows, if the mapping is done by the        tenant/customer:

-   1. Operators exposes the network capability in terms of different    type of network slices (i.e. network slice as a service). The    tenant/customer asks for multiple network slices for its service.

-   2. The tenant/customer defines one or more per slice service    requirements.

-   3. The tenant/customer requires the network to report the    performance of all the slices.

-   4. In case of a performance change of an individual network slice,    the tenant/customer can adjust the requirements for each associated    slice considering the E2E service requirements.    -   The procedure may be as follows, if the mapping is done by the        network (particularly the apparatus 100 and/or 300 provided in        the network):

-   1. The tenant/customer defines one or more overall service    requirements.

-   2. The network maps the tenant/customer service to multiple slices    (e.g. via CSMF)

-   3. The network reports the overall performance of the service to the    tenant/customer.

-   4. In case of a performance change of an individual network slice,    the network adjusts the requirements for each associated slice

Next, a method and procedure for correlated slice instantiation andmanagement considering multiple subnets is described in detail. Thedetails are described with respect to the reference architecture shownin FIG. 6 as an example. A similar procedure, however, can be derivedfor other architectures (e.g. 3GPP SA5, 5G-MoNArch architecture, 5GPPParchitecture WG, etc.).

-   Step 1: Design a Slice Template (finer granularity service KPIs,    e.g., for multiple slices) and onboarding.-   Step 2: BSS sends the order (one or multiple associated services) to    communication service layer.-   Step 3: Communication service layer transfers the order into slice    initiation request (including multiple slices and correlation    (binding) information 102)-   Step 4: For each slice SSS initiate the E2E slice instance 304:    -   4.1 Negotiate and confirm the latency quota with each DSM.    -   4.2 Get initiation parameters from request, plan pool and        inventory and generate E2E slice initiation plan.    -   4.3 Separate plan into several domain slice initiation requests        (including slice correlation information) and send them to DSMs.-   Step 5: DSM initiates the sub-slice instance:    -   5.1 Generate sub-slice initiation plan considering slice        correlation and fulfill it.    -   5.2 Report the initiation process to SSS.-   Step 6: SSS Subscribe the KPI from DSMs after instance initiation.-   Step 7: DSM reports the KPI to SSS periodically, DSM performs local    inter slice optimization considering slice correlation.-   Step 8: SSS aggregates KPIs into E2E KPIs and shows them on KPI    dashboard, SSS performs cross slice optimization considering slice    correlation.

The present disclosure has been described in conjunction with variousembodiments as examples as well as implementations. However, othervariations can be understood and effected by those persons skilled inthe art and practicing the claimed disclosure, from the studies of thedrawings, this disclosure and the independent claims. In the claims aswell as in the description the word “comprising” does not exclude otherelements or steps and the indefinite article “a” or “an” does notexclude a plurality. A single element or other unit may fulfill thefunctions of several entities or items recited in the claims. The merefact that certain measures are recited in the mutual different dependentclaims does not indicate that a combination of these measures cannot beused in an advantageous implementation.

1. An apparatus for network slicing, the apparatus comprising: aprocessor; and a non-transitory computer-readable storage medium coupledto the processor and having stored thereon a program includingprocessor-executable instructions for: determining at least twocorrelated communication traffic flows for a service; and binding the atleast two correlated communication traffic flows and generating bindinginformation; wherein the processor is configured to execute theprocessor-executable instructions of the program.
 2. The apparatusaccording to claim 1, wherein the program further includesprocessor-executable instructions for receiving a request for a service,and wherein the processor-executable instructions for determining the atleast two correlated communication traffic flows for the service areinstructions for determining the at least two correlated communicationtraffic flows for the service based on at least the request orpre-configured information.
 3. The apparatus according to claim 2,wherein at least the request for the service or the pre-configuredinformation includes information regarding the at least two correlatedcommunication traffic flows.
 4. The apparatus according to claim 3,wherein the request for the service includes information about arespective session of each of the at least two correlated communicationtraffic flows, and wherein the request for the service further includesnetwork slice selection assistance information for each respectivesession and/or an identity of each respective session.
 5. The apparatusaccording to claim 4, wherein the program further includesprocessor-executable instructions for storing a list of sessionsassociated with at least slice selection assistance information orsession identities for the at least two correlated communication trafficflows.
 6. The apparatus according to claim 1, wherein the request forthe service includes one or more service requirements, and wherein theprocessor-executable instructions for determining the at least twocorrelated communication traffic flows for the service are instructionsfor determining the at least two correlated communication traffic flowsfor the service based on the one or more service requirements.
 7. Theapparatus according to claim 1, wherein the program further includesprocessor-executable instructions for exposing the binding informationat least in at least one network layer or to at least one other networkentity.
 8. The apparatus according to claim 1, wherein the programfurther includes processor-executable instructions for: authenticatingthe received request for the service; and mapping the service to the atleast two correlated communication traffic flows.
 9. The apparatusaccording to claim 1, wherein the binding of the at least two correlatedcommunication traffic flows is performed at a network layer.
 10. Anapparatus for network slice management, comprising: a non-transitorycomputer-readable storage medium coupled to the processor and havingstored thereon a program including processor-executable instructionsfor: converting a service requirement of a tenant or application into ajoint performance parameter in correlated network slice instances;determining a resource allocation for at least one of the correlatednetwork slice instances based on the joint performance parameter,wherein the processor is configured to execute the processor-executableinstructions of the program.
 11. The apparatus according to claim 10,wherein the program further includes processor-executable instructionsfor exposing a joint performance parameter to one or more functions inthe network layer.
 12. The apparatus according to claim 10, wherein theprogram further includes processor-executable instructions forinstantiating the at least two correlated network slice instances for aservice based on the resource allocation.
 13. The apparatus according toclaim 10, wherein the program further includes processor-executableinstructions for instantiating at least two sub-slices in at least oneof the correlated network slice instances based on the resourceallocation.
 14. The apparatus according to claim 10, wherein the programfurther includes processor-executable instructions for receiving acommunication traffic flow binding information from the network layer.15. The apparatus according to claim 10, wherein the program furtherincludes processor-executable instructions for monitoring at least thejoint performance parameter or the resource allocation at least acrossthe at least two correlated network slice instances or across twocorrelated communication traffic flows.
 16. The apparatus according toclaim 10, wherein the program further includes processor-executableinstructions for exposing at least the joint performance parameter orthe resource allocation at least across the at least two correlatednetwork slice instances or across at least two correlated communicationtraffic flows to the tenant or application.
 17. The apparatus accordingto claim 15, wherein the program further includes processor-executableinstructions to apply a joint quality of service (QoS) treatment to theat least two correlated network slice instances or at least twocommunication traffic flows based on at least the joint performanceparameter or the binding information.
 18. The apparatus according toclaim 13, wherein the program further includes processor-executableinstructions for: managing the at least two correlated network sliceinstances or the at least two sub-slices based on at least the jointperformance parameter or the resource allocation by applying a jointresource management across the at least two correlated network sliceinstances or the at least two sub-slices; or performing a serviceoptimization across the at least two correlated network slice instancesor at least two sub-slices in at least two correlated network sliceinstances.
 19. A method for network slicing, the method comprising:determining at least two correlated communication traffic flows for aservice; and binding the at least two correlated communication trafficflows and generating binding information.